Use safely: Follow these steps only for a router or network you own or are authorised to manage. Never send Router Portal a router password, Wi-Fi key, MAC address, serial number or private screenshot.
Evidence and scopeSOURCE-BACKED · CHECK DATE
Sources2 official references
ScopeModel/OS/network dependent
CredentialsNever universal
ReviewRecheck after UI changes
Quick answer: Two active DHCP servers can hand out different gateways or DNS settings, making only some devices fail.
What this page covers
Compare DHCP-server and gateway fields from two clients, then isolate the unauthorised router or extender.
Step-by-step workflow
- Capture configuration fields from two affected clients privately.
- Identify every router, access point, extender and hotspot attached by Ethernet.
- Disconnect one suspected device at a time from the LAN.
- Keep the intended DHCP authority and retest new leases.
Decision table
| Check | What it tells you | Safe next action |
|---|---|---|
| Different gateways | Clients are receiving different offers | Find the second DHCP source |
| Different DNS servers | DHCP scopes or policy differ | Compare router LAN settings |
| Only guest devices fail | Intentional isolation may be involved | Check the guest network design |
Limits and verification
Do not disable a provider-managed gateway without understanding bridge, voice, TV or support dependencies.
Official sources
- IETF RFC 2131 — Dynamic Host Configuration Protocol (DHCP message and lease concepts)
- CISA — Securing Home Network Devices (home-network safety guidance)
Related Router Portal guides
Find the current gateway · Router security guide
Editorial note: This pilot page is written for one distinct question. Firmware, operating-system menus, ISP policies and regional radio rules can change, so confirm the source and exact device before applying a setting.